Abstract
Effects of CCA (disodium 4-chloro-2, 2'-iminobenzoate) on the production of plaque forming cells (PFC) in murine spleens were investigated and the following findings and results were obtained in this paper. (1) CCA had almost no effect on anti SRBC PFC responses at optimal experimental conditions in normal animals but had at some suboptimal condi-tions. (2) In T cell-deficient nude mice, CCA increased the percent of Thy-1+ cells in the spleen and enhanced the product ion of PFC to T-dependent antigen such as SRBC. CCA also showed an enhancing effect on the production of PFC to T-independent antigen, LPS. (3) Induction of suppressor T cells by Con A in the spleen of NZB/W F1 mice in which the activity of these cells are known to be decreased was enhanced by the treatment of CCA. (4) From the above findings. CCA seems to affect both helper and suppressor T cells and B cells. 5 Such a multiple action of CCA on lymphocytes populations may explain the mechanism by which CCA does not affect the normal immune responses but does the hyper-or hypo-immune responses resulting from the deficiency and the impainment of a specific lymphocyte population as observed in the case of nude mice or NZB/W F1 mice.
